Attachment to turbine-blades.



L. GUBELIC. ATTACHMENT 0I TUBBINB BLADES, APDLIcATloN FILED JULY 31, 1913.

Patented Jan, 27, 1914.

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MJ/ WM spaced apart at suitable intervals by approvention; Fig. 2 is a transverse section ornion.

LUDWIG CUBELIC, OF CHARLOTTENBURG, GERMANY, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ATTACHMENT OF TURBINE-BLADES.

Specification of Letters Patent.

Application file d July 31, 1913. Serial No. 782,228.

To all w/om t may concern.'

Be it known that I, LUDWIG CUnnLiC, a I

subject of the King of Prussia, residing at Charlottenburg, Germany, have invented certain new andj useful Improvements in the Attachment of Turbine-Blades, of which the l following..is a specification.

My invention relates to the attachment ofv blades, buckets, or guides to turbine rotors i or to stationary elements of the turbine casing and the like, and more particularly to the securing of such blades in under-cut slots or grooves. Y

Turbine blades, buckets, or guides are frequently made from-drawn strips of material of suitable cross-section cut at one end in such a manner that they have dovetail or otherwise appropriately shaped base portions adapted to fit in a similarly shaped under cut groove in the periphery of the bucket wheel or drum or in the turbine cas ing,` or some other stationary part. The blades are then inserted ,in the groove and riately shaped space blocks. To enable the Blades to be readily put in place, it is usual to interrupt the edges or the sides of the groove for a short distance to provide an opening that will accommodate the bases of the blades. Aft/er all the blades have been put in lace, this opening is filled with an inset fil er block or securing member which keeps the two blades between which it lies with their edges within theunder-cut groove at the ends oi the space or opening. Thisl mode of construction has the-defect that the bases of the blades on opposite sides of the securing block are usual y* but just barely in the roove, and that it sometimes happens that t ere is sufficient looseness or shifti of the arts to permit these blades to wor out o? the groove, 4or even that owing to oor workmanship', they are not really in t e groove at all to begin with,- with the result that they are thrown out by centriu l force during the operation of the turbine. By my invention this defect is overcome.

In the accompanying drawing, Figure 1 is a plan View of a portion of the periphery of a turbine bucket wheel showing two blades, secured in place according toniy intlirough the rim ofthe wheel; vand Fig. 3

is a mid-section through the blades and the rim.

It will be seen from the above figures that the bucket wheel rim l has an dunder-cut groove 2, the cross-section of this groove being indicated by the dotteu lines 3, 3 in Fig. 2. Most of the blades 4, 4, etc., it will be seen, arc merely inserted with their correspondingly cnt bases 5 in this groove 2 and spaced apart by the space blocks 6. At 7, however, the side walls of the groove 2 are interrupted or cut away in the manner above described to provide for the insertion of the last two blades 8 and 9, the side walls of the space thus afforded being themselves, however, under-cut as indicated at l0, 10. These two last or end blades 8 and 9 are shown as differing from the remaining blades 4, 4 in that at the side of the base of each that lies away from the other there is provided an associated or even integral space-block, projection, offset, or thickening 11 which extends toward the adjacent blade si, the Space blocks 12, 12 between the Shanks of these special blades 8 and 9 and those of the next blades 4 on either side being made correspondingly thinner. When, therefore, the

securing filler block 13 is inserted in the space 7 and secured in place by being forced home on the conical pin, 14, the two end blades 8 and 9 have quite an extended grip in the under-cut groove 2, so that no loose ness which might exist could possibly result in their becoming displaced. If desired, transverse pins '15 may for greater security be passed t rough holes in the wheel riin 1 and in the projections 11 on the blades S and 9 and riveted in place. i

In accordance with the provisions of thel patent statutes, have described the p'rinciple of operation of my invention, together with the apparatus which now consider to represent the' best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is:-

1. The combination with a member having` an nnder-cut groove therein and a plurality of turbine blades with their ends engagged in said groove, of two adjacent blades each having a. shank portion 'with un offset Patenten Jan. er, wir.

5 tions extending into the groove, and a liller blocksecured in said space between said blades.

2. In an elastic fluid turbine, the combination of a rotary member having an under- 10 cut groove therein, the walls of said groove being interrupted to permit of the insertion of the blades, a plurality of blades having bases Whichlare tted into said groove, space blocks between said bases, and a pair of special blades located at said interruption, 15 said blades having on opposite sides space blocks formed integral therewith, and a lilling block secured between said special blades.

In witness whereof, I have hereunto set 20 my hand this 15 day of July 1913.

LUDWIG CUBELIC.

Witnesses FRIEDRICH GANzERs, O'l'ro SCHMIDT. 

